352 Mr. G. Dollmin on Arvicanthis abysslnicus 



Dimensions in millimetres (measured in the fleali) : — 



Average of 



8 adults. Max. Min. 



Head and body 127 134 120 



Tail 99 108 94 



Hind foot 24 25 23 



Adult skull (type) : greatest length 30'-i mm. ; basilar 

 length 26; condylo-incisive lengtii 2y*9 ; zygomatic breadth 

 16 ; squamosal breadth of cranium 12; interorbital constric- 

 tion 5 ; length of nasals 12*7 ; palatilar length 14'3 ; length 

 of palatal loraTuina 6'5 ; alveolar length of upper molar 

 series 6. 



Type locality. Shuk, Northern Somaliland, 



Type in British Museum, no. 97. 12. 3. 9. 



Since this species was described Dr. Drake-Brockman has 

 presented to the Museum a series of Arvicanthi'i from Upper 

 jSheikh, Sonuililand, and these specimens, although rather 

 richer in colour than the type, apj)arently represent the true 

 somalicus. 



(IG) Arvicunthi's reptans, Dollm. 



Arvicanthis reptans, Dollman, Ann. & Mag. Nat. Hist. (8) viii. p. 129 

 (1011). 



The smallest species of the ahyssinicas group at present 

 known ; allied to somal'icus. 



Size of body small, average length 114 mm.; tail and hind 

 foot much as in somalicus. General colour above pinkish 

 brown speckled with black, the black tint most evident down 

 the middle of the back. Flanks rather more buff-coloured 

 than back, sbarj)ly marked off' from the white ventral surface. 

 Hairs of back with black bases, butf-coloured subterminal 

 rings, and dark tips. Ocular rings, nose, and ears bright 

 orange-buff". Backs of hands and feet light bufty orange. 

 Under surface of body greyish white tinted with buif. Tail 

 as in somalicus, dark blackish brown above and light butf 

 below. 



Skull like that of somalicus, but smaller and less elongate, 

 lilolar teeth rather small. 



Dimensions in millimetres (uieasurod in the ile^h) : — 



Average of 



10 adults. Max. Min. 



Head and bodv 114 121 100 



Tail '. 97 111 87 



Hind foot 24 2") L>i>o 



